Inline 6 upgrades and recomendations???

[passthebuck]

You can do a few upgrades to an L6 head. The normal polish/3 angle, etc. The big problem is the headbolt passage that runs right through the centre of the intake port. I've heard of guys machining it out, adding an access plug in the roof of the port & using a lowprofile allenhead bolt that sits on the bottom of the port. Since the head is comparitively long, they tend to almost always need to be machined flat too. 250's use 307 pistons so you can easily get performance pistons.